18. 
Refer
to the exhibit. Routers A, B, C, and D are all running OSPF with default router
IDs and OSPF interface priorities. Loopback interfaces are not configured and
all interfaces are operational. Router D is the DR and router C is the BDR.
What happens immediately after the following commands are entered on router A?
A(config)#
interface fa0/0
A(config-if)#
ip ospf priority 255